The present invention refers to a screen element for sorting and classifying a fluid flow, in particular for use in the paper industry for treating suspensions or for mechanical purification of molasses in the sugar industry. In particular, the invention refers to a screen element which is provided with classifying openings at the side facing the incoming fluid flow and with bores at the other side which extend over a plurality of classifying openings and are in communication therewith.
It is known to make the walls of screen elements in sandwich construction by combining a thin fine screen with a support screen. Screen elements of this type have the drawback that the perforations in the fine screen in the area of the webs of the support screen are not utilized.
EP-PS 14 66 41 describes a screen basket which is provided at one side thereof with classifying openings of small diameter and at the other side thereof with bores of largerdiameter which are in communication with the classifying openings. Such a screen basket requires relatively complicated and cumbersome repair work in case the fine screen becomes defective. Moreover, since the fine screen is fixedly secured to the support screen, an adjustment of the perforations or classifying openings to suit varying demands upon classification and sorting is limited.